论文标题
银河球状簇的等异隆拟合 - iv。 NGC6362和NGC6723
Isochrone fitting of Galactic globular clusters -- IV. NGC6362 and NGC6723
论文作者
论文摘要
我们向银河球状簇NGC \，6362和NGC \ \，6723的颜色 - 磁性图提出了新的异弦。我们使用{\ it Hst}，{\ it iT gaia}，Unclisce，Unclisce，Unclise和其他光度法来源的数据集分别利用NGC \，6362和NGC \，6723的22和26光度过滤器。我们使用达特茅斯恒星进化数据库（DSED）的型号和等线，以及$α$增强的[$α$/fe] $ =+0.4 $和不同的氦气丰度，并以$α$增强的[$α$/fe]的范围（basti）（basti）（basti）。金属性[Fe/H] $ = -1.04 \ PM0.07 $和$ -1.09 \ PM0.06 $分别源自我们适合NGC \，6362和NGC \ ngc \，6723的红色巨型分支斜坡。他们同意文献的光谱估计。由于邻近的Corona Australis Cloud Complex，我们发现NGC \ 6723场中的差异最高为$ΔE（B-V）= 0.13 $ mag。我们分别为NGC \，6362和NGC \，6723得出以下内容：距离$ 7.75 \ pm0.03 \ pm0.15 $（统计和系统错误）和$ 8.15 \ pm0.04 \ pm0.04 \ pm0.15 $ kpc;年龄$ 12.0 \ pm0.1 \ pm0.8 $和$ 12.4 \ pm0.1 \ pm0.8 $ gyr;灭绝$ a_ \ mathrm {v} = 0.19 \ pm0.04 \ pm0.06 $和$ 0.24 \ pm0.03 \ pm0.06 $ mag;红粉丝$ e（b-v）= 0.056 \ pm0.01 \ pm0.02 $和$ 0.068 \ pm0.01 \ pm0.02 $ mag。与巴斯蒂相比，DSED具有系统地降低[Fe/H]和更高的红粉丝。但是，这些模型在其相对估计中达成共识：NGC \，6723为$ 0.44 \ pm0.04 $ kpc，$ 0.5 \ pm0.1 $ gyr offer，$δe（b-v）= 0.007 \ pm0.002 $ 0.05 \ pm0.05 \ pm0.01 $ dex lows ng/h] 63 33. $ 0.05 \ pm0.01 $ h]。 NGC \，6723相对于NGC \，6362解释其水平分支形态差异。这确认年龄是这些簇的第二个参数。我们提供{\ it Gaia}数据版本3的群集成员的列表。
We present new isochrone fits to the colour-magnitude diagrams of the Galactic globular clusters NGC\,6362 and NGC\,6723. We utilize 22 and 26 photometric filters for NGC\,6362 and NGC\,6723, respectively, from the ultraviolet to mid-infrared using data sets from {\it HST}, {\it Gaia}, unWISE, and other photometric sources. We use models and isochrones from the Dartmouth Stellar Evolution Database (DSED) and Bag of Stellar Tracks and Isochrones (BaSTI) for $α$-enhanced [$α$/Fe]$=+0.4$ and different helium abundances. The metallicities [Fe/H]$=-1.04\pm0.07$ and $-1.09\pm0.06$ are derived from the red giant branch slopes in our fitting for NGC\,6362 and NGC\,6723, respectively. They agree with spectroscopic estimates from the literature. We find a differential reddening up to $ΔE(B-V)=0.13$ mag in the NGC\,6723 field due to the adjacent Corona Australis cloud complex. We derive the following for NGC\,6362 and NGC\,6723, respectively: distances $7.75\pm0.03\pm0.15$ (statistic and systematic error) and $8.15\pm0.04\pm0.15$ kpc; ages $12.0\pm0.1\pm0.8$ and $12.4\pm0.1\pm0.8$ Gyr; extinctions $A_\mathrm{V}=0.19\pm0.04\pm0.06$ and $0.24\pm0.03\pm0.06$ mag; reddenings $E(B-V)=0.056\pm0.01\pm0.02$ and $0.068\pm0.01\pm0.02$ mag. DSED provides systematically lower [Fe/H] and higher reddenings than BaSTI. However, the models agree in their relative estimates: NGC\,6723 is $0.44\pm0.04$ kpc further, $0.5\pm0.1$ Gyr older, $ΔE(B-V)=0.007\pm0.002$ more reddened, and with $0.05\pm0.01$ dex lower [Fe/H] than NGC\,6362. The lower metallicity and greater age of NGC\,6723 with respect to NGC\,6362 explain their horizontal branch morphology difference. This confirms age as the second parameter for these clusters. We provide lists of the cluster members from the {\it Gaia} Data Release 3.
